Undecided what an SMTP error code means? You’re not alone. It may be stunning and complicated to see SMTP errors generally, and we wish to eradicate the confusion with a quick-and-easy clarification.
Under, we’ll clarify every little thing you have to learn about SMTP error codes, together with quick explanations of widespread ones you’ve doubtless seen earlier than.
What’s an SMTP error code?
Throughout the SMTP course of, messages are relayed from one pc to a different by way of SMTP servers. SMTP servers ship response codes that point out what has occurred to messages.
Whereas messages are normally despatched with out situation, completely different server response codes can point out numerous issues.
Under are a handful of SMTP server response codes that we’ve compiled that you simply would possibly see when sending emails.
Widespread SMTP error codes
- SMTP 250: This SMTP server response merely means every little thing went nicely and your message was delivered to the recipient server.
- SMTP 421: Your message was briefly deferred by the recipient server. That is normally a results of too many connections in a brief timeframe or too many messages.
- SMTP 450: Your message was not delivered as a result of the opposite person mailbox was not accessible. This will occur if the mailbox is locked or shouldn’t be routable.
- SMTP 451: This response is distributed when the message merely failed. Typically occasions this isn’t attributable to you, however quite due to a far-end server drawback.
- SMTP 452: This sort of response is distributed again when there isn’t sufficient system storage to ship the message. Your message is deferred till storage opens up and it might then be delivered.
- SMTP550: The message has failed as a result of the opposite person’s mailbox is unavailable or as a result of the recipient server rejected your message.
- SMTP 551: The mailbox your message was meant for doesn’t exist on the recipient server.
- SMTP 552: The mailbox your message was despatched to doesn’t have sufficient storage to just accept your message.
- SMTP 553: Your message was not delivered as a result of the title of the mailbox you despatched it to doesn’t exist.
- SMTP 554: This can be a very imprecise message failure response that may seek advice from any variety of issues both in your finish or with the recipient server.
There are a selection of points that may set off these SMTP server responses, and also you’re not anticipated to know the best way to deal with all of them. SendGrid’s wonderful help employees is right here that can assist you determine what went improper and what you are able to do to appropriate it.
Begin sending with Twilio SendGrid
To study extra about these and different SMTP server responses, learn our Information Base article. The article gives examples of all these responses in addition to presents recommendations for correcting any issues.
Sending e-mail entails a number of computer systems speaking with one another by means of a course of name Easy Message Switch Protocol (SMTP). SendGrid capabilities as an SMTP relay service to ship billions of promoting and transactional emails each month.
Join a free account (no bank card required) to begin sending!
